Toughened Glass or Tempered Glass is a type of glass that has increased strength and will usually shatter into small fragments when broken. Toughened glass is strong, has enhanced thermal resistance, and breaks into small cuboid fragments rather than irregular shards of glass.

Toughened glass is used when strength, thermal resistance and safety are important considerations, such as in microwavable see-through cookware. Other forms of tempered glass are Borosilicate glass for baking by Pyrex and Arcuisine, ceramic-glass dinnerware by Corelle and Arcopal and bakeware and stovetop pots by Arcoflam. Within the home, tempered glass can be found in display case windows, shower doors, glass patio doors, glass dinnerware and drinking glasses.

In commercial structures, tempered glass is used for unframed assemblies such as frameless doors, structurally loaded applications and any that would be dangerous in the case of a human impact. Japanese farmers also found that growing fruits such as watermelons in a tempered glass form, will cause the fruit to become that shape.

Toughened glass is made from annealed glass via a thermal tempering process. The glass is placed onto a roller table, taking it through a furnace that heats it to above its annealing point of 600 °C. The glass is then rapidly cooled with forced draughts of air while the inner portion of the glass remains free to flow for a short time.